HEDAS has run near real time since the 2010 hurricane season. The following schematic describes the mechanics of how HEDAS works:

The positive impact of aircraft observations for vortex-scale data assimilation has been demonstrated using a large sample of hurricane cases with aircraft data. These results are summarized in Aksoy et al. 2013.

During the 2013 hurricane season, satellite retrieved wind and thermodynamic observations were assimilated in addition to traditional aircraft-based observations. Some of the latest results from the 2013 runs are summarized in the the first half of a recent talk by Altug Aksoy. The following figure summarizes HEDAS' 2013 performance in terms of verifications of HWRF forecasts initialized with the HEDAS vortex:

From the figure, it is clear that forecasts initialized with a HEDAS vortex analysis are improved in terms of both track and intensity when compared to the operational HWRF forecasts. Furthermore, the addition of satellite retrieval observations to our traditional aircraft dataset appears to make further improvements in intensity. Due to the limited number of cases verified especially at longer lead times, while these results by no means should be interpreted as comprehensive, it is nevertheless encouraging to see that advanced data assimilation techniques with high-quality observations do make a difference in TC forecasts. A further indication of forecast improvements can be also found in the following figure, which shows the number of cases verified for each forecast configuration tested:

The fact that the number of cases that can be verified increases as satellite data are assimilated in addition to aircraft data indicates that forecasts initialized with vortex analyses that assimilated satellite data are able to maintain the initial vortex for longer lead times than just aircraft data.

Our recent results with satellite AMVs plus AIRS and GPS-RO retrieval observations were summarized in a poster that was recently presented at the American Meteorological Society's 31st Conference on Hurricanes and Tropical Meteorology in San Diego, California: